In general, a room lamp of a vehicle includes a function of manually controlling a button and the like based on user convenience or turning on the room lamp when a door of the vehicle is opened. Currently, the room lamp of the vehicle includes a function of turning off the room lamp while automatically decreasing illumination of the room lamp slowly when the door of the vehicle is closed. Further, the room lamp that does not interfere with a driver by transforming a housing of the room lamp of the vehicle has been invented.
However, the room lamp of the related art does not adaptively cope with a light change in an environment of the vehicle, which may cause user inconvenience. For example, when children ride together, a driver usually turns on the room lamp while driving at night. In this case, it is highly probable that the driver may feel eye fatigue caused by the room lamp or that a reaction velocity of the driver may become slow due to light reflection resulting from the room lamp. Further, when a scanning direction of light of the room lamp is not consistently oriented to the driver due to a housing of the room lamp, the room lamp may not irradiate light with the high illumination toward the driver when stopping.